Varnish

Varnish Cache is a web accelerator also called as a caching HTTP reverse proxy. You can install it in front of any server that speaks HTTP and configure it to cache the content. Varnish Cache is really, really fast and will boost the speed of your website. One of the main virtues of Varnish Cache is the flexibility of its domain-specific language, VCL, which permits you to define how incoming requests should be dealt with.

Memcached

Memcached is a generic memory object caching system for boosting the loading speed of dynamic database-powered web sites. It is used to decrease the number of times an external data source (such as a database or API) is read by caching data and objects in RAM. The Memcached system uses a two-tier architecture. The Memcached memory caching system is used by some of the most frequently visited sites on the World Wide Web and is supported by famous web apps like Joomla and WordPress.

Node.js

Node.js is a platform for writing scalable Internet applications. Written in JavaScript, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and efficient, ideal for high-performance data-heavy apps. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source database management system. A database engine is the primary software component that a DBMS uses to create, retrieve, modify and delete data from a database. The latest release of InnoDB offers considerable improvements in performance, reliability and usability. InnoDB provides the standard ACID-compliant database transaction attributes, as well as referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.